Peripheral reset timings

[Kraal]

Hello,
I have a question regarding the peripheral reset registers.
For the G070 device, in the RM0454, section 5.2.16, it is specified that the clock enable of a peripheral takes 2 cycles to prevent glitches. Fine.
However, how do you experts use the reset registers ? Let's say that you want to reset the CRC peripheral.
I'm doing it like so for the moment:

RCC->AHBENR |= RCC_AHBENR_CRCEN; // Turn ON CRC peripheral clock
delay_us(5);
RCC->AHBRSTR = RCC_AHBRSTR_CRCRST; // Reset peripheral
delay_us(5);
RCC->AHBRSTR = 0;
delay_us(5);

But I don't know if any delays are indeed needed or not here. Any thought on this ?

Best regards,
Kraal

[TDK]

There's no need to use the reset registers on an initial powerup as the registers will all be at their initial values.

[Kraal]

Thanks but that is not an answer to the question. If you jump from a bootloader to an application you might want to reset an already configured and used peripheral to its reset state.

[Pavel A.]

This is an interesting topic. See these threads for example:

https://community.st.com/t5/stm32-mcu-products/erratum-quot-delay-after-an-rcc-peripheral-clock-enabling-quot/m-p/580729#M220378

https://community.st.com/t5/stm32-mcu-products/inline-assembly-macro-inconsistent/m-p/580743#M220384

Bottom line: unless very restricted in time, delay for a *few* clocks. Use a reliable method for the delay.